When it is not possible or appropriate to completely eliminate ...

[kamilo84]

When it is not possible or appropriate to completely eliminate the event or activity used as a contingent reinforcer this variation of the reversal design can be employed.
 
  a. B-A-B
  b. B-A-C-A
  c. NCR Reversal
  d. Multiple Treatment Reversal

Question 2

Discuss the difference between observer drift and observer reactivity.
 
  What will be an ideal response?

[shayla]

Answer to Question 1

C

Answer to Question 2

Observer drift usually entails a shift in the observer's interpretation of the definition of the target behavior from that used in training. The drift causes unintended changes in the way data are collected and may produce measurement error. Observer reactivity may also cause measurement errors, however these errors are the result of the observer's awareness that others are evaluating the data.